The global aim of the proposed research is to continue the study of comprehension processes within and between different modalities. This will involve comparing and contrasting spoken and written language, but will also focus on contrasts between other cognitive domains. In the previous funding period a number of informative experiments were conducted which provided a better understanding of the comprehension processes that are unique to and shared by the modalities/domains. However, this research has left a number of issues unresolved and has generated a new set of questions which serve as the basis for the current proposal. The approach used will entail the recording of event-related potentials (ERPs) from electrodes placed over a number of brain regions while human subjects engage in experiments designed to tap comprehension processes both within and across modalities/domains. One long term goal, for which these studies provide a framework, will be to study comprehension processes in normal children and children with specific reading disabilities. There are 4 sets of specific aims and corresponding groups of experiments. 1. Structure Building Studies. We have proposed that Gernsbacher's Structure Building model of comprehension best accounts for a variety of findings with the N4OO ERP component. This hypothesis will be tested in a series of four experiments. If evidence favoring this interpretation is found, then we will use the N4OO to examine the predictions of this model in subsequent studies. 2. Picture Processing Studies. In these experiments work on the similarity of picture and word priming will be extended to short stories based on both still pictures and dynamic (moving) images. These will be compared to written versions of the same stories. 3. Neighborhood Studies. The literature on neighborhood size (the number of other words which resemble a target word) has revealed a difference in the direction of effects for spoken and written words, with larger neighborhoods facilitating written words, but inhibiting spoken words. In four sets of experiments we will compare and contrast the effects of neighborhood size across modalities. 4. Cross-modality & Cohort Studies. We have found evidence that spoken and written words use a common conceptual system during comprehension. However, one finding which persisted across several experiments was that spoken words, but not written words or pictures, were much less effective primes (semantic and repetition) at short prime/target intervals. To address this asymmetry two experiments are proposed which will manipulate parameters of auditory prime stimuli. The goal of other studies will be to determine if a sentence context can modify the time- course of spoken word processing in a manner consistent with Marslen- Wilson's Cohort model.